BTW, did you make a mental note of who has the remaining honors in hearts? And how many hearts do you think that player has? Did you use apply the rule of 11 at trick one?
Recommended line of play: You have a nine card diamond fit, so dummy’s diamonds should run if they split no worse than 4-0. You are in dummy, having won with the nine of hearts. Play a low diamond from dummy and insert the jack. Even if it loses to the queen, you know the diamond split is no worse than 3-1. And the remaining diamonds are sure to take tricks. You see how, don’t you? If not, please ask me.
When I observed the play on this hand declarer led the ace of diamonds at trick two, playing the two from his hand. It was not possible to recover after that. Bottom line: It’s right to recognize diamonds as your source of tricks, but make sure you retain an entry (the ace of diamonds in this example) to cash them.